In-vitro fertilization is associated with a high rate of multiple pregnancies, a consequence of the number of embryos transferred. There is a challenge in avoiding even twin pregnancies in assisted reproduction, and this can be accomplished with elective single embryo transfer and a good cryopreservation programme. In our follow-up study, we analysed all our elective single embryo transfers dur...

background: effect of seasonal changes in human reproduction has been intensively researched. some studies acknowledge influences of seasonal variation on natural conception, while others can not confirm them. the aim of this study was to investigate the effect of seasonal changes on different stages of assisted reproductive technology (art) in tehran. materials and methods: this study was carr...

background: the values of embryonic stem cell and cloning are evident. production of clone from embryonic stem cells can be achieved by introduction of stem cell into a tetraploid blastocyst. tetraploid blastocyst can be produced in vitro by electrofusion of 2-cell embryos. objective: the aim of this study was to assess the effect of different voltages and durations on fusion rate of bovine 2-c...

The aim of this work is to study the effect of the vitrification procedure on prenatal survival and on placental development at the end of gestation in rabbits (Oryctolagus cuniculus). One hundred eighty-one females were slaughtered at 72 h of gestation. Morphologically normal embryos recovered at 72 h of gestation were kept at room temperature until transfer or vitrification. Vitrified embryos...

The objective of this study was to assess whether the exposure of zona pellucida-intact bovine embryos to the proteolytic enzyme, trypsin, during embryo washing has a detrimental effect on their subsequent survival and development. Embryos were collected nonsurgically from superovulated cows (n = 19) 7.5 d after insemination. Grade 1 and Grade 2 embryos were washed 12 times in modified Dulbecco...

The DBA/2J mouse strain is a standard laboratory strain that is widely used for biomedical research. This strain, however, suffers from poor reproductive performance. In addition, the conditions for reliable embryo transfer (ET) of this strain have not been elucidated. The intention of this study was to determine the optimal number of embryos for transfer that allow the effective production of ...